21. Harry travels from Appleton to Brockiey at an evernge speed of 50 mph. He then travels from Brockley to Cantham at an average speed of 70 mph. Harry takes a total time of5 hours to travel from Appleton to Cantham. The distance from Brockley To Cantham is 210 miles. Calculate Harry's average speed for the total distance travelled from Appleton to Cantham.

To calculate Harry's average speed, we need to find the total distance and time taken. Step 1: Determine the time it takes for Harry to travel from Brockley to Cantham. This can be found using the speed formula: . So, rearranging for time gives us . Thereby, Time (Brooklyn to Cantham) = .Step 2: Given that the total time to travel from Appleton to Cantham was 5 hours and time from Brooklyn to Cantham is 3 hours. The actual time from Appleton to Brooklyn will be \( \text{Time} (Appleton to Brooklyn) = 5 \text{ total hours} - 3 \text{ hours} =2 \text{ hours} \).Step 3: Calculate the distance from Appleton to Brockley. Knowning derived time from previous step and Speed (Appleton to Brockley) = 50 mph from the question directly. Therefore, Distance (Appleton to Brockley) = Speed(Brockley)*Time .Step 4: Having those above inferred, compute total distance (Appleton to Cantham) by adding those partial distance decided above. The total distance (Appleton to Cantham) \(= \text{Dist}(Appleton to Brockley) + \text{Dist}(Brockley to Cantham) = 100 \text{ miles} + 210 \text{ miles} = 310 \text{ miles}\).Step 5: Introduced at step4, apply distance feeble to figuring out Distance (Appleton to Cantham) and given knowledge that time spent on the entire trip(Appleton to Cantham) -- 5 hours, now, revisit speed calculation formula ( enhanced version), average speed , .